Improving gut health and performance of broilers by adding Bacillus subtilis to the diet

dc.contributor.advisorJansen van Rensburg, Christineen
dc.contributor.coadvisorPlumstead, Peteren
dc.contributor.emailu28011164@tuks.co.zaen
dc.contributor.postgraduateCoertze, Gerharden
dc.date.accessioned2015-11-25T09:53:59Z
dc.date.available2015-11-25T09:53:59Z
dc.date.created2015/09/01en
dc.date.issued2015en
dc.descriptionDissertation (MScAgric)--University of Pretoria, 2015.en
dc.description.abstractThe purpose of the study was to evaluate the benefits, if any, of adding a probiotic product containing Bacillus subtillus to the diet of broilers. The study was conducted in an open-sided house, with curtains and a coal boiler (HEATCO) attached to a heat sock. The house contained 64 pens in total, divided into 2 rows of 32 pens each over the length of the house. The pens were covered with used chicken litter (4cm deep). Three thousand six hundred Ross 308 broiler birds were feather-sexed and randomly distributed throughout the pens, 60 broilers of the same sex per pen at a stocking density of 20 birds/ m2. All broilers received similar typical South African maize-soya diets throughout the study. Diets were treated with antibiotic growth promoters (AGP) and / or direct-fed-microbials (DFM) to create six treatments as follows: Negative Control: Basal diet (without AGP), Positive Control: Basal diet (with AGP), DFM at 500g/ton (without AGP), DFM at 250g/ton (without AGP), DFM at 500g/ton (with AGP), and DFM at 250g/ton (with AGP). Broiler performance was measured weekly in terms of body weight (BW), feed intake (FI) and feed conversion ratio (FCR) from day old to 35 days of age. Birds were culled at day old, as well as 22 days of age for the isolation of Avian Pathogenic E. coli (APEC), E. coli and Lactobacillus from the gastrointestinal tract. Males showed a higher feed intake from 14 to 35 days of age compared to females, even though the FCR remained similar between sexes (P > 0.05). There were no dose response between DFM 500g/ton and DFM 250g/ton, as well as between DFM 500g/ton + AGP and DFM 250g/ton + AGP (P > 0.05) in terms of BW, FI and FCR. Positive Control had a higher body weight, no difference in feed intake and lower FCR compared to Negative Control at 35 days (P < 0.05). A lower dose of DFMs (250g/ton) in the diets of broilers revealed a significantly lower FCR compared to diets without DFMs (Negative Control), and DFM (500g/ton and 250g/ton) + AGP, and no significant difference in FCR compared to DFM (500g/tom) and Positive Control. However, when combining a DFM with AGP in the diet, the FCR of broilers increased due to a lower weight obtained with a higher feed intake at 35 days. The DFM (500g/ton) + AGP had a significantly lower BW compared to Positive Control at 35 days, although, revealed no significant difference in terms of FI (P > 0.05), but a significantly higher FCR at 35 days compared to Positive Control (P < 0.05). DFM (250g/ton) without AGP tend to lower the feed intake (P < 0.05) of broilers compared to AGPs, but when combining a DFM with AGP, the feed intake increased significantly (P < 0.05), revealing a higher FCR (P < 0.05) compared to AGPs and DFM (250g/ton). The recommendation will be to use a lower dose of DFM (250g/ton) as an alternative for AGP in broiler diets.en
dc.description.availabilityUnrestricteden
dc.description.degreeMScAgricen
dc.description.departmentAnimal and Wildlife Sciencesen
dc.description.librariantm2015en
dc.identifier.citationCoertze, G 2015, Improving gut health and performance of broilers by adding Bacillus subtilis to the diet, MScAgric Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/50857>en
dc.identifier.otherS2015en
dc.identifier.urihttp://hdl.handle.net/2263/50857
dc.language.isoenen
dc.publisherUniversity of Pretoriaen_ZA
dc.rights© 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.en
dc.subjectUCTDen
dc.titleImproving gut health and performance of broilers by adding Bacillus subtilis to the dieten
dc.typeDissertationen

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